[SI-LIST] Re: masking of PCB from x-rays
- From: olaney@xxxxxxxx
- To: si-list@xxxxxxxxxxxxx
- Date: Wed, 19 Sep 2007 09:10:09 -0700
There is always the approach used by one huge Fortune 100 company to
stave off competition. Silkscreened onto the motherboard in the original
IBM PC was the blunt warning "NO COPYING PERMITTED".
Orin
On Wed, 19 Sep 2007 09:21:28 -0400 "Russell S. Dudek Jr."
<rdudek@xxxxxxxxxxxxxxx> writes:
> Koshy,
>
> Although your approach for masking x-rays may be useful for other
> considerations aside from copy protecting, i.e. hardening. If
> someone
> really wants to replicate your artwork, they will find a way.
> Personally,
> the (destructive) approach that I would use to reverse engineer a
> PCB is by
> horizontal cross sectioning. Unfortunately, your x-ray shielding
> would not
> stand up to this method.
>
> RD
>
> -----Original Message-----
> From: si-list-bounce@xxxxxxxxxxxxx
> [mailto:si-list-bounce@xxxxxxxxxxxxx] On
> Behalf Of Clewell, Craig
> Sent: Wednesday, September 19, 2007 9:02 AM
> To: 'thomas.koshy@xxxxxxxxxxx'
> Cc: si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] Re: masking of PCB from x-rays
>
> Koshy,
>
> Perhaps some kryptonite might work as this has been known to thwart
> superheroes.
>
> If that doesn't work I think thick dense materials like tungsten,
> mercury,
> uranium and lead will stop the x-rays. X-rays are absorbed and/or
> scattered by electrons in a material. So to stop x-rays is you have
> to pack
> as many electrons as possible into the smallest amount of space.
> Lead is a
> material that is capable of doing this and is cheaper and less toxic
> than
> the other materials I mentioned above.
>
> Just a couple of quick thoughts that you may find useful.
> 1. Try cutting up a lead pencil (if you can find one) and put the
> lead over
> the traces.
> 2. If you have a couple of thermometers lying around you may be able
> to lay
> these over the traces. Since this may mask the finished product you
> may
> need to take multiple views and then cut/paste them together.
>
> CC
>
>
> -----Original Message-----
> From: ThomasKoshy Conzerv IN HO Sr Technical Lead iLabs
> [mailto:thomas.koshy@xxxxxxxxxxx]
> Sent: Wednesday, September 19, 2007 03:15
> To: si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] masking of PCB from x-rays
>
> Sir,
> I am interested to mask the components on a printed circuit board
> from
> X-rays to avoid copying the same. Could you pl. suggest an easy
> method?
>
> Thanks.
>
> Koshy
>
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